#!/bin/sh

documentation="\
Recursively fix permissions on the given directories to allow GID=0
read/write regular files and read/write/execute directories.

To run this command, you have to be in the group root=0!"

uid=26
write=w

usage ()
{
    cat >&2 <<EOF
$0: Error: ${1-usage error}

Usage: $0 [--read-only] DIR [DIR ..]

$documentation
EOF
    exit 1
}

while test $# -gt 0; do
    case $1 in
    --read-only) write= ; shift ;;
    *) break ;;
    esac
done

test $# -eq 0 && usage "no DIR specified"

for dir; do
    test -d "$dir" || usage "no such directory '$dir'"
    echo >&2 "fixing permissions on '$dir' directory"
    find "$dir" -exec chown "$uid:0" {} \;
    find "$dir" -exec chmod "g+r$write" {} \;
    find "$dir" -type d -exec chmod g+x {} +
done